The present invention is directed to an enossal implant for a firmly seated tooth replacement, which implant includes a fastening device having a fastening head in an implant post connectible to a base element via a thread connection, said base element being selected from a base body and a metal spacer part threadably recieved in the base body and the distal end of the base element being separated from a portion of the implant post by a concentrically surrounding intermediate element made of an elastic plastic material, such as polyoxymethylene.
U.S. Pat. No. 5,026,280, whose disclosure is incorporated herein by reference thereto and which claims priority from German Application 38 39 274, discloses an enossal implant in which a metallic spacer part is threaded into one end of a threaded bore of a base body until it engages an upper shoulder along the upper edge of the body. A plastic intermediate element concentrically surrounds an implant post which is threadably engaged in the spacer art so that the intermediate element is entrapped between the spacer part and the tooth replacement. The implant post can be threaded into the spacer part while pressing a bearing surface of the tooth replacement facing the intermediate element onto a stop shoulder of the intermediate element remote from the spacer part. The enossal implant has excellent cushioning characteristics, but does not insure a satisfactory restraint to twisting of the tooth replacement with respect to the base body and, therefore, the jaw bone, unless special measures, such as bending and the like, are adopted. The known implant is, therefore, only suitable to a limited extent for use as a single tooth implant. This unsatisfactory solution for providing a restraint to twisting can also be at a disadvantage in other cases.
U.S. Pat. No. 5,026,285, whose disclosure is incorporated herein by reference thereto and which claims priority from German Application 39 17 690, is directed to an enossal single tooth implant for a firmly seated tooth replacement in which the spacer part comprises a two-part metallic spacer bushing which can be threaded into the base body and whose two parts are locked to one another and to the base body. Such locking together will lead to a twist-restrained connection between the base body and the spacer bushing's top and bottom parts. If a corresponding twist-restrained fixing is insured, this enables the tooth replacement to be connected in a twist-restrained manner to one of the last-mentioned parts of the spacer bushing. The known enossal single tooth implant has proven satisfactory, but makes it necessary to use special locking tools which can be difficult to use in certain cases.